A screen for recessive speciation genes expressed in the gametes of F1 hybrid yeast.
A screen for recessive speciation genes expressed in the gametes of F1 hybrid yeast.
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DOI：
10.1371/journal.pgen.0030021
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发表时间：
2007-02-16
期刊：
影响因子：
4.5
通讯作者：
Greig, Duncan
中科院分区：
文献类型：
--
作者：
Greig, Duncan
酿酒酵母和它的近亲奇异酵母的二倍体杂交体是可行的，但它们产生的有性配子不是。这种配子不能存活的几个可能原因之一是来自不同物种的基因之间的不相容性--这种不相容的基因通常被称为“物种形成基因”。在含有每个物种完整单倍体基因组的二倍体F1杂种中，相容等位基因的存在可以掩盖（隐性）不相容物种形成基因的影响。但在F1杂种产生的单倍体配子中，隐性物种形成基因可能暴露出来，杀死配子，从而阻止F1杂种进行有性繁殖。在这里，我提出了一个实验的结果，以检测杀死杂交配子的不相容性。我把16个S中的9个调走了。paradoxus染色体分别转化为S.酿酒酵母配子和测试的能力，每一个取代其S。酿酒酵母同源物所有9条染色体都是相容的，产生了9个有活力的单倍体菌株，每个菌株有15个S。酿酒酵母染色体和一个S.奇异染色体因此，这些染色体中没有一条含有能够杀死接受它们的杂交配子的物种形成基因。这是一个令人惊讶的结果，表明这种物种形成基因在酵母物种形成中不起主要作用。一个物种通常被定义为这样，因为它不能与其他物种交换基因。近缘物种可能会尝试繁殖，但不成功。一个常见的例子是驴和马交配。这种交配的后代是一种叫做骡子的杂种。骡子是不育的，不能繁殖，所以驴和马是作为不同的物种保持的，它们不能交换基因。了解杂交后代不育的原因可以告诉我们新物种是如何起源的。这项研究不是用骡子，而是用不育的酵母杂交种，因为它们产生的性细胞（相当于精子或卵子的酵母）是死的。一个可能的原因是来自不同物种的基因在性细胞中无法协同工作，从而杀死了它们。为了验证这个想法，我用另一个物种的染色体替换了一个物种性细胞中的单个染色体。令人惊讶的是，这并没有杀死配子，这表明来自一个物种的基因可以与另一个物种的基因很好地工作。并不是所有的基因都可以用这种方法进行测试，但尽管如此，酵母杂交产生的性细胞的死亡似乎很可能是由不同物种的基因无法一起工作而引起的。
Diploid hybrids of Saccharomyces cerevisiae and its closest relative, Saccharomyces paradoxus, are viable, but the sexual gametes they produce are not. One of several possible causes of this gamete inviability is incompatibility between genes from different species—such incompatible genes are usually called “speciation genes.” In diploid F1 hybrids, which contain a complete haploid genome from each species, the presence of compatible alleles can mask the effects of (recessive) incompatible speciation genes. But in the haploid gametes produced by F1 hybrids, recessive speciation genes may be exposed, killing the gametes and thus preventing F1 hybrids from reproducing sexually. Here I present the results of an experiment to detect incompatibilities that kill hybrid gametes. I transferred nine of the 16 S. paradoxus chromosomes individually into S. cerevisiae gametes and tested the ability of each to replace its S. cerevisiae homeolog. All nine chromosomes were compatible, producing nine viable haploid strains, each with 15 S. cerevisiae chromosomes and one S. paradoxus chromosome. Thus, none of these chromosomes contain speciation genes that were capable of killing the hybrid gametes that received them. This is a surprising result that suggests that such speciation genes do not play a major role in yeast speciation. A species is usually defined as such because it cannot exchange its genes with other species. Closely related species may attempt to breed but be unsuccessful. A common example of this occurs when a donkey mates with a horse. The offspring of this mating is a hybrid called a mule. Mules are sterile and cannot reproduce, so donkeys and horses are maintained as distinct species—they cannot exchange genes. Understanding what makes hybrids sterile could tell us how new species originate. Instead of mules, this study examines yeast hybrids that are sterile because the sex cells (the yeast equivalent of sperms or eggs) they produce are dead. One possible reason for this is that the genes from the different species fail to work together in the sex cells, killing them. To test this idea, I replaced individual chromosomes in one species' sex cells with chromosomes from another species. Surprisingly, this did not kill the gametes, showing that the genes from one species can work fine with the genes of another. Not all the genes could be tested in this way, but nevertheless it seems likely that the death of sex cells produced by yeast hybrids is caused by something other than failure of the genes from different species to work together.
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影响因子：
64.8
作者：
Kellis, M;Patterson, N;Lander, ES
通讯作者：
Lander, ES
影响因子：
5.3
作者：
DUTCHER, SK
通讯作者：
DUTCHER, SK
影响因子：
7
作者：
Cliften, PF;Hillier, LW;Johnston, M
通讯作者：
Johnston, M
DOI：
10.1098/rspb.2002.1989
发表时间：
2002-06-07
影响因子：
4.7
作者：
Greig, D;Borts, RH;Travisano, M
通讯作者：
Travisano, M
影响因子：
64.8
作者：
Fischer, G;James, SA;Louis, EJ
通讯作者：
Louis, EJ